Special purpose fluid dispenser

ABSTRACT

A compact, nonelectric fluid dispenser for use in controllably dispensing beneficial agents such as propofol and dexmedetomidine hydrochloride to patients. The dispenser includes a fluid flow control assembly that precisely controls the flow of the medicament solution to the patient and embodies a collapsible drug container that can be filled in the field with the beneficial agents to be delivered to the patient. The unit-dose fluid dispenser of the invention is presented in a sterile and aseptic manner, where the drug has been pre-filled in the system, so that the practitioner cannot mistakenly give the wrong drug to the patient. The dispenser uniquely provides a more efficient medicament delivery system for procedure rooms, such as the endoscopy center, so that a greater number of patients can be treated per day at a higher standard of care with increased profits for the healthcare provider.

FIELD OF THE INVENTION

The present invention relates generally to fluid dispensing devices. More particularly, the invention concerns a novel dispenser for dispensing propofol, as well as analogous sedation agents, to patients with increased safety and efficiency while reducing the probability of hospital acquired infections.

DISCUSSION OF THE PRIOR ART

A number of different types of medicament dispensers for dispensing various types of medicaments to patients have been suggested in the past. The traditional prior art infusion methods make use of a flexible infusion bag suspended above the patient. Such gravametric methods are cumbersome, imprecise, require many time consuming steps by clinicians, are susceptible to medication errors and require bed confinement of the patient. Periodic monitoring of the apparatus by the nurse or doctor is required to detect malfunctions of the infusion apparatus. Accordingly, the prior art devices are not well suited for use in those instances where the patient must be transported from one part of the healthcare facility to another.

Many of the state-of-the-art medicament delivery devices involve the use of electronic pumps to dispense the medicament from the dispenser reservoir. In the past, these types of devices have been the devices of choice for dispensing propofol (and other injectable sedation agents) and this equipment requires significant effort to prepare and administer the drug.

Propofol is a highly protein bound in vivo and is metabolised by conjugation in the liver. Its rate of clearance exceeds hepatic blood flow, suggesting an extrahepatic site of elimination as well. Its mechanism of action is uncertain, but it is postulated that its primary effect may be potentiation of the GABA—a receptor, possibly by slowing the closing channel time. Recent research has also suggested the endocannabinoid system may contribute significantly to Propofol's anesthetic action and to its unique properties.

In recent years propofol has been widely used as an anesthetic agent for the induction of general anesthesia in adult patients and pediatric patients older than 3 years of age, for use in the maintenance of general anesthesia in adult patients and pediatric patients older than 2 months of age, for use in sedation for intubated, mechanically ventilated adults, and in procedures such as colonoscopy.

At the present time, propofol is commonly delivered through an electronic pump that is preset with the patient's weight (in kg) and a dosage increment measured in micrograms/kg/min. One prior art electronic pump that is presently in use is a pump sold by Baxter International, Inc, of Deerfield, Ill. under the name and style “InfusO.R.”. This pump contains four separate dials. The first dial is to set the patient weight; the second dial is to set the dosage; the third dial is to set a bolus volume to initiate sedation; and the fourth dial is used to purge the syringe if there is any remaining propofol after the procedure. The Baxter pump has a magnetic plate that contains all the increments of the dials and the plates can be changed for different medications. By having removable plates, there is an increased possibility of medication error if the magnetic plate is not checked for increments for the correct medication or the correct concentration. The Baxter pump is typically used in the surgicenter setting where the anesthesiologist gives the patient an initial bolus of propofol for inducing sedation and the preset dosage is given in addition to gas anesthesia to keep the patient asleep during the operation. Another pump that is presently in use is a pump sold by the Cardinal Health Company of Dublin, Ohio under the name and style “ALARIS PL”. The ALARIS PL syringe pump or ALARIS IVAC pump is used in conjunction with a Diprifusor syringe that is pre-filled with propofol. The Diprifusor is a target controlled infusion (TCI) system that was developed to enhance the control of IV anesthesia. With a TCI pump, a microprocessor manages the infusion rate and controls the syringe. The anesthesiologist enters the body weight of the patient, the age of the patient, and the dosage in microgram/ml. The Alaris pumps rely on the anesthesiologist entering the correct data minimizing the possibility of medication error but the dosage form is not the commonly used increment, (microgram/ml instead of microgram/kg/min) which relies on the anesthesiologist to convert the dosage and potentially increases the risk of medication error through miscalculation. The Diprifusor and TCI pumps are typically used in Europe where the pump is used to control sedation and anesthesia, but are thus far not dominant in the American surgical market.

As will be discussed in greater detail hereinafter, the propofol dispenser of the present invention allows the anesthesiologist to create a basic “recipe” for propofol based sedation that could prevent patient complications. The dispenser of the present invention is particularly well-suited for use in the administration of propofol by non-anesthesiologists in low risk procedures, such as colonoscopies.

Another pharmaceutical agent appropriate for use in this novel dispenser technology is dexmedetomidine hydrochloride (Precedex), and related compounds. Precedex is indicated for sedation of initially intubated and mechanically ventilated patients during treatment in an intensive care setting. Precedex is typically administered by continuous infusion using a syringe of the drug fluid (drawn up in a non-aseptic environment by the anesthesiologist) and dispensed by an electronic pump. Precedex is being used with patients in the intensive care unit (ICU), during neurosurgery and for children during MRI.

Precedex is delivered via intravenous infusion over a selected amount of time through a controlled infusion with the use of an electronic or battery operated pump or with a “smart pump”. A pre-filled and non-electric pump that is therapy specific could allow more widespread use of novel sedation agents (such as Precedex), because of the ability to administer the therapy in a safer and more efficient manner without the need for multiple steps and sophisticated software routines.

The novel dispenser of the present invention provides numerous advantages over prior art devices including the following:

Creation of a standard operating procedure for the administration of propofol by anesthesiologists and non-anesthesiologists alike.

Elimination of the need for filling syringes, thereby reducing the potential for medication errors due to filling (i.e. using the wrong concentration of propofol) or use of a drug that is similar in appearance to propofol.

Elimination of the need for an electronic pump, thereby reducing the potential for medication error due to incorrect settings.

Reducing costs to healthcare providers and practitioners by eliminating expensive electronic capital equipment that requires continuous maintenance, calibration and cleaning.

Elimination of the requirement for electricity in austere or chaotic environments (e.g. during military engagements, natural disasters).

Presentation of the sedation agent at the point of care in an aseptic manner (via the field fill design where the dispenser is filled at time of use by engagement of the drug and device through a polarized sterile coupling), should also minimize the probability of hospital acquired infection.

As previously mentioned, a significant market for the small volume dispenser of the present invention is the endoscopy center market. In this regard, one form of the dispenser of the present invention is specially designed for relatively short procedures (i.e. 20-30 minutes), such as colonoscopies and endoscopies. More particularly, the dispenser of the invention, which is non-electric and disposable following use, can provide an extremely cost effective means of increasing efficiency in the endoscopy center. The dispenser uniquely provides an alternative to expensive electronic pumps that are often complicated and time consuming to operate. In addition, low cost disposable devices for use in outpatient clinics are consistent with a broader theme in healthcare that is aimed at lowering costs while improving quality of care and patient outcomes. Because physicians in the endoscopy center are searching for a cost effective means to increase patient throughput within the center, the dispenser of the present invention provides a natural fit for a standardized sedation process for colonoscopies and endoscopies, without compromising the quality and safety of the procedure.

In another form of the present invention, the dispenser comprises a mid-volume propofol delivery systems technology (65 ml) that is specially designed for use in the surgicenter for procedures that require sedation times of 1-2 hours. In this application a novel dispenser can serve as a safe and effective means for patients that are to be fitted with orthopedic and cardiac implants. Similarly, this novel mid-volume dispenser can function well with minimum discomfort for general surgeries such as hernia repairs and the like. Because physicians in the surgicenter market are often quite time conscious, the dispenser of the present invention comprises a natural fit for a standardized sedation process that could potentially increase patient throughput within the market without compromising the quality and safety of the procedure. Additionally, patients prefer propofol as an anesthetic agent because there is no “hangover” effect, which stems from its ease of titration and rapid elimination half-life. By way of comparison, traditional anesthesia with gas has a very slow elimination half-life and patients require long recovery times that are typically complicated by nausea and vomiting. Conversely, propofol has inherent antiemetic properties, which chemically combats feelings of nausea.

In yet another form of the present invention, the dispenser comprises a large volume propofol dispenser (250 ml) that is specially designed for use in military applications, including total IV anesthesia (TIVA) by the Forward Surgical Team at the battlefield, as well as for sedation of the patient during transport from one echelon of care to the next. This form of the invention can provide a safe and effective means to sedate a patient during an operation and throughout transport without relying on bulky medical equipment or expensive equipment that is transported with the patient and never returned to the original care facility.

As will be fully appreciated from the discussion that follows, the devices of the present invention are also particularly useful in ambulatory situations. The ability to quickly and efficaciously treat wounded soldiers, especially in unpredictable or remote care settings, can significantly improve chances for patient survival and recovery. Accurate intravenous (IV) drug and fluid delivery technologies for controlling pain, preventing infection, and providing a means for IV access for rapid infusions during patient transport are needed to treat almost all serious injuries.

It is imperative that battlefield medics begin administering life saving medications as soon as possible after a casualty occurs. The continuous maintenance of these treatments is vital until higher echelon medical facilities can be reached. A compact, portable and ready to use infusion device that could be easily brought into the battlefield would allow medics to begin drug and resuscitation agent infusions immediately. Additionally, it would free them to attend to other seriously wounded patients who may require more hands-on care in the trauma environment following triage. In most serious trauma situations on the battlefield, IV drug delivery is required to treat fluid resuscitation, as well as both pain and infection. Drug infusion devices currently available can impede administration of IV infusions in remote care settings.

Expensive electronic infusion pumps are not a practical field solution because of their weight and cumbersome size. Moreover, today's procedures for starting IV infusions on the battlefield are often dangerous because the attending medic must complete several time consuming steps. The labor intensive nature of current gravity solution bag modalities can prevent medics from attending to other patients also suffering from life threatening injuries. In some cases, patients themselves have been forced to hold flexible infusion bags elevated, in order to receive the medication by gravity drip.

SUMMARY OF THE INVENTION

By way of brief summary, one form of the dispensing device of the present invention for dispensing the beneficial agent, such as propofol, to a patient comprises a housing, a carriage assembly disposed within the housing, a reservoir defining assembly carried by the carriage, a stored energy means operably associated with the carriage for moving the carriage between a first position and a second position to expel from the reservoir the fluid medicament contained therein, and flow control means to control the flow of fluid from the reservoir, the flow control means uniquely comprising dose control means for controlling the dose of medicament to be delivered to the patient and rate control means for controlling the rate of medicament flow to the patient. This novel design would therefore allow the physician to set a medicament flow rate based on the patient's body weight in kg and the patient appropriate dose in micrograms per kg per hour.

With the forgoing in mind, it is an object of the present invention to provide a compact, nonelectric fluid dispenser for use in controllably dispensing propofol to patients.

Another object of the invention is to provide a fluid dispenser of simple construction that can be used in the field with a minimum amount of training.

Another object of the invention is to allow infusion therapy to be initiated quickly and easily on the battlefield so that the attending medic or medical professional can more efficiently deal with triage situations in austere environments.

Another object of the invention is to provide a dispenser of the class described which includes a fluid flow control assembly that precisely controls the flow of the medicament solution to the patient.

Another object of the invention is to provide a dispenser that includes precise variable flow rate selection.

Another object of the invention is to provide a fluid dispenser of simple construction, which embodies a collapsible drug container that can be selectively filled with the beneficial agent at the point of care.

Another object of the invention is to provide a fluid dispenser of the class described which is compact, lightweight, is easy and safe for providers to use, is fully disposable, transportable, and is extremely reliable in operation.

Another object of the invention is to provide a fluid dispenser of the class described that is presented in a sterile and aseptic manner where drug filling is conducted at the point of care; so as to minimize the probability of hospital acquired infections and medication errors.

Another object of the invention is to provide a medicament dispenser that improves the process efficiency of the healthcare setting by streamlining the tasks associated with the preparation, administration and monitoring of drug delivery of regimen.

Another object of the invention is to provide a low cost single-use alternative to expensive electronic pumps that have to be continually cleaned, calibrated and maintained at tremendous costs to healthcare providers.

Another object of the invention is to provide a dispenser that can administer anesthesia and sedation agents to patients without problematic side effects, such as nausea and vomiting, typically encountered with traditional gas anesthesia.

Another object of the invention is to provide a more efficient medicament delivery system for procedure rooms, such as the endoscopy center, so that a greater number of patients can be treated per day at higher standard of care with increased profits for the healthcare provider.

Another object of the invention is to provide a fluid dispenser as described in the preceding paragraphs that is easy and inexpensive to manufacture in large quantities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a generally perspective front top view of one form of the fluid dispensing device of the present invention for dispensing medicaments to a patient.

FIG. 2 is a generally perspective rear bottom view of the fluid dispensing device shown in FIG. 1.

FIG. 3 is a top plan view of the fluid dispensing device shown in FIG. 1.

FIG. 4 is a side view of the fluid dispensing device shown in FIG. 3.

FIGS. 5 and 5A, when considered together, comprise an enlarged cross-sectional view of the fluid dispensing device shown in FIG. 4 of the drawings.

FIG. 6 is an enlarged, top plan view, partly in cross-section, of the central portion of the fluid dispensing device shown in FIG. 1.

FIG. 7 is a cross-sectional view taken along lines 7-7 of FIG. 6.

FIG. 7A is a top plan view of the fluid pickup plates of the bolus delivery subassembly of the apparatus.

FIG. 7B is a cross-sectional view taken along lines 7B-7B of FIG. 7A.

FIG. 8 is a cross-sectional view taken along lines 8-8 of FIG. 7.

FIG. 9 is a cross-sectional view taken along lines 9-9 of FIG. 7.

FIG. 10 is a cross-sectional view taken along lines 10-10 of FIG. 7.

FIG. 11 is a cross-sectional view taken along lines 11-11 of FIG. 7.

FIG. 12 is a top plan view of the patient weight selector knob and the patient dose selector knob components of the fluid dispensing device.

FIG. 13 is a cross-sectional view taken along lines 13-13 of FIG. 12.

FIG. 14 is a cross-sectional view taken along lines 14-14 of FIG. 12.

FIG. 15 is an enlarged front view of the main body portion of the dispensing apparatus shown in FIG. 1.

FIG. 16 is an enlarged cross-sectional view taken along lines 16-16 of FIG. 15.

FIG. 17 is an enlarged cross-sectional view taken along lines 17-17 of FIG. 15.

FIG. 18 is an enlarged cross-sectional view of the rearward portion of the fluid dispensing device shown in FIG. 1, further illustrating construction of the field filled reservoir portion of the device.

FIG. 19 is a cross-sectional view taken along lines 19-19 of FIG. 18.

FIG. 19A is a generally perspective, diagrammatic view illustrating the path of fluid flow through the device during the reservoir filling step.

FIG. 20 is an enlarged top plan view of the patient weight selector subassembly of the fluid dispensing device.

FIG. 21 is a cross-sectional view taken along lines 21-21 of FIG. 20.

FIG. 22 is an enlarged, generally perspective exploded view of the patient weight selector subassembly of the fluid dispensing device.

FIG. 23 is a bottom plan view of the upper rate control plate of the patient weight selector subassembly illustrated in FIG. 22 and showing in phantom lines the main fluid pickup housing of the device.

FIG. 24 is a cross-sectional view taken along lines 24-24 of FIG. 23 showing the main fluid pickup housing device in greater detail.

FIG. 25 is a fragmentary view taken along lines 25-25 of FIG. 24 showing only one half of the main fluid pickup housing and illustrating the construction of the anti-rotational grooves thereof.

FIG. 26 is a cross-sectional view taken along lines 26-26 of FIG. 23.

FIG. 27 is a generally diagrammatic view illustrating the main fluid pickup housing of the device shown in the upper portion of FIG. 24 as it would appear in flat configuration.

FIG. 28 is a top plan view of the fluid connector boss of the fluid delivery device illustrated in FIG. 22.

FIG. 29 is a side elevation view of the fluid connector boss shown in FIG. 28 illustrating the configuration of the fluid micro pickup of the connector boss.

FIG. 30 is a cross sectional view taken along lines 30-30 of FIG. 28.

FIG. 31 is a top plan view of the upper rate control plate of the patient weight selector subassembly illustrated in FIG. 22.

FIG. 32 is a cross-sectional view taken along lines 32-32 of FIG. 31.

FIG. 33 is a cross-sectional view taken along lines 33-33 of FIG. 31.

FIG. 34 is a view taken along lines 34-34 of FIG. 31.

FIG. 35 is a cross-sectional view taken along lines 35-35 of FIG. 31.

FIG. 36 is a top plan view of the rate control plate of the fluid delivery device illustrated in FIG. 22.

FIG. 37 is a cross-sectional view taken along lines 37-37 of FIG. 36.

FIG. 38 is a view taken along lines 38-38 of FIG. 36.

FIG. 39 is a cross-sectional view taken along lines 39-39 of FIG. 36.

FIG. 40 is a top plan view of the bottom rate control plate of the fluid delivery device illustrated in FIG. 22.

FIG. 41 is a side elevation view of the rate control assembly retaining cover of the fluid delivery device.

FIG. 42 is a cross-sectional view taken along lines 42-42 of FIG. 41.

FIG. 43 is a cross-sectional view taken along lines 43-43 of FIG. 41.

FIG. 44 is a view taken along lines 44-44 of FIG. 41.

FIG. 45 is a view taken along lines 45-45 of FIG. 41.

FIG. 46 is a top plan view of the patient weight selector knob of the patient weight selector subassembly of the fluid delivery device.

FIG. 47 is a cross-sectional view taken along lines 47-47 of FIG. 46.

FIG. 47A is a generally diagrammatic view illustrating the portion of the patient weight selector knob shown in the lower portion of FIG. 47 as it would appear in flat configuration.

FIG. 48 is a cross-sectional view taken along lines 48-48 of FIG. 47.

FIG. 49 is a view taken along lines 49-49 of FIG. 47.

FIG. 49A is a view taken along lines 49A-49A of FIG. 49.

FIG. 50 is a top plan view of the patient dose selector knob of the patient dose selector subassembly of the fluid delivery device.

FIG. 51 is a view partly in cross-section taken along lines 51-51 of FIG. 50.

FIG. 52 is a view taken along lines 52-52 of FIG. 51.

FIG. 53 is a generally diagrammatic view illustrating the portion of the patient dose selector knob shown in the lower portion of FIG. 51 as it would appear in flat configuration.

FIG. 54 is an end view of the fluid delivery device shown in FIG. 1.

FIG. 55 is a cross-sectional view taken along lines 55-55 of FIG. 54 illustrating the construction of the bolus operating mechanism of the fluid delivery device.

FIG. 56 is a fragmentary cross-sectional view illustrating the construction of the bolus interlock mechanism of the fluid delivery device.

FIG. 57 is a generally perspective, exploded view of the bolus operating mechanism.

FIG. 58 is a top plan view of the bolus reservoir of the apparatus.

FIG. 59 is a cross-sectional view taken along lines 59-59 of FIG. 58.

FIG. 60 is a view taken along lines 60-60 of FIG. 59.

FIG. 61 is a top plan view of the bolus selector subassembly of the apparatus.

FIG. 62 is a cross-sectional view taken along lines 62-62 of FIG. 61 illustrating the construction of the main bolus and secondary plunger assembly portion of the bolus operating mechanism.

FIG. 63 is a view taken along lines 63-63 of FIG. 62.

FIG. 64 is a top view of the main reservoir operating shaft.

FIG. 65 is a cross-sectional view taken along lines 65-65 of FIG. 64.

FIG. 66 is a cross-sectional view taken along lines 66-66 of FIG. 64.

FIG. 67 is a cross-sectional view taken along lines 67-67 of FIG. 64.

FIG. 68 is a cross-sectional view taken along lines 68-68 of FIG. 62.

FIG. 69 is a cross-sectional view taken along lines 69-69 of FIG. 68.

FIG. 70 is a cross-sectional view similar to FIG. 68, but showing the operating spring of the bolus plunger assembly in a compressed condition.

FIG. 71 is a cross-sectional view taken along lines 71-71 of FIG. 68.

FIG. 72 is a cross-sectional view taken along lines 72-72 of FIG. 68.

FIG. 73 is a top view of the secondary reservoir operating shaft of the bolus plunger assembly.

FIG. 74 is a cross-sectional view taken along lines 74-74 of FIG. 73.

FIG. 75 is a view taken along lines 75-75 of FIG. 74.

FIG. 76 is a view taken along lines 76-76 of FIG. 74.

FIGS. 77, 78 and 79 are generally perspective views of the bolus operating mechanism of the invention illustrating the sequential steps to be followed in operating the mechanism to accomplish the delivery to the patient of bolus doses.

DESCRIPTION OF THE INVENTION

Referring to the drawings and particularly to FIGS. 1 through 5, one form of the fluid dispensing apparatus of the present invention for dispensing medicaments such as propofol to a patient is there shown and generally designated by the numeral 100. The dispensing apparatus here comprises a device housing 102 having a forward portion 104, a rear portion 106 and a central portion 107. Device housing 102 can be constructed from metal, plastic or any suitable material.

Disposed within the rear portion 106 of device housing 102 is a “carriage” assembly 108 that is movable between a first rearward position shown in FIG. 5 and a second advanced position. As best seen by referring to FIGS. 5, 18 and 19, carriage assembly 108 comprises a carriage 110 having a carriage flange 112 to which the novel stored energy means of the present invention is operably interconnected. As will be discussed in greater detail hereinafter, this stored energy means is here provided in the form of a coil spring 148 that is movable from the first compressed position to a second extended position. Carriage assembly 108 is releasably locked in its first position by a novel locking means the character of which will be described in the paragraphs which follow.

Carried by carriage assembly 108 is a reservoir defining assembly 114 that defines a fluid medicament reservoir 115. As illustrated in FIG. 5, reservoir defining assembly 114 includes a front portion 114 a, a rear portion 114 b and an accordion-like, collapsible side wall 114 c that interconnects the front and rear portion of the assembly. As illustrated in the drawings, the accordion like side wall 114 c comprises a multiplicity of adjacent generally “V” shaped interconnected folds. Rear portion 114 b of the assembly includes a protuberance 116 that includes a rear wall 116 a. As best seen in FIG. 5, cup-shaped protuberance 116 is closely receivable within a cavity 120 formed in carriage 110. Reservoir assembly 115 also includes a forward neck portion 122.

Reservoir 115 has an outlet 124 (see FIG. 5) that is formed in a fluid transfer block 128 that forms a part of the rear portion 106 of housing 102. As illustrated in FIG. 5 of the drawings, fluid transfer block 128 includes a reduced diameter portion 128 a to which the front portion 114 a of the reservoir defining assembly is sealably interconnected. Fluid transfer block 128 also includes a fluid fill passageway 130 and a vent passageway 132 (FIG. 6). Fluid fill passageway 130 is in communication with a sterile coupling assembly 134 that as best seen in FIG. 6 of the drawings is mounted within a cavity 136 formed in fluid transfer block 128. Fluid fill passageway 130 as well as sterile coupling assembly 134 form a part of the fill means of the invention for filling fluid reservoir 115 with the fluid to be dispensed to the patient. In the present form of the invention sterile coupling assembly 134 comprises a body portion 138 that houses a pierceable slit septum 140 and a conventional, umbrella check valve 142. Umbrella check valve 142, which is housed within a cavity 144 that is in communication with fill passageway 130, functions to permit fluid flow in a direction toward fluid reservoir 115, but blocks fluid flow in the opposite direction. With this construction, fluid reservoir 115 can be conveniently filled with propofol or other sedation agents in a conventional manner through the use of a conventional syringe “S”, such is that shown in FIG. 19A of the drawings having either a sharp, or blunt end needle that is capable of piercing septum 140.

To move carriage assembly 108 from its first at rest position to its second advanced position and to thereby controllably expel the fluid from the fluid reservoir 115, stored energy means are provided. This stored energy means, which is operably associated with carriage assembly 108, is here provided in the form of a coil spring 148 that is movable from the first compressed position shown in FIG. 5 to a second extended position, which causes the carriage assembly to move toward its second advanced position and in so doing to cause the collapse of the accordion side wall of the reservoir defining assembly. As the accordion side wall of the reservoir defining assembly collapses, the fluid “F” contained within the fluid reservoir 115 will be controllably expelled from the reservoir through the fluid outlet 122. As the fluid is expelled from a fluid reservoir, any gases contained within the fluid reservoir will be vented to atmosphere, via passageway 132, through a vent port 146 that is carried by fluid transfer block 128 (FIG. 6).

To control the flow of fluid from reservoir 115 toward the administration set 153 of the invention (FIG. 2) and then on to the patient, novel fluid flow control means are provided. This fluid flow control means here comprises a flow rate control assembly 156 and a dose control assembly 334, both of which will be presently described in greater detail. The fluid flow control means, which is carried by the central portion 107 of housing 102, here comprises dose control means for controlling the dose of medicament to be delivered to the patient and rate control means for controlling the rate of medicament flow from collapsible reservoir 115 toward the dose control means.

As will presently be discussed in greater detail, the rate control means here comprises a flow rate control assembly 156 that includes a first rate control plate 158 and a second rate control plate 160, each of which is provided with a plurality of fluidic micro-channels. The rate control means also includes a rate control distribution plate 292, a fluid pickup housing 294 and a rotatable patient weight selector knob 312. The rate control means further includes a rate control indexing means here provided as a locking plunger 333 that is carried by housing 102. Fluid pickup housing 294 is provided with six vertically spaced apart, transversely extending fluid passageways 330 that, upon rotation of the patient weight selector knob 312, communicate with selected ones of the circumferentially spaced outlet ports 316 formed in patient weight selector knob 312. Fluid passageways 330 communicate with the dose control means of the invention which functions to control the dose of medicament to be delivered to the patient.

As will be discussed in greater detail hereinafter, this dose control means comprises the dose control assembly 334 that includes a rotatable patient dose selector knob 338. The dose control means further includes dose control indexing means, here provided in the form of a locking plunger 353 that is carried by housing 102 that functions to lock the patient dose selector knob 338 in any selected position.

Considering first the rate control means component of the fluid flow control means, as best seen in FIGS. 5, 7, 9 and 20 through 49, this novel means here comprises a flow rate control assembly 156 (FIGS. 7 and 9) for controlling the rate of fluid flow toward the dose control means. Flow rate control assembly 156 includes a first, or lower rate control plate 158 and a second, or upper, rate control plate 160 (FIGS. 7, 9, 36 and 40). As best seen in FIG. 40, bottom side of rate control plate 160 is uniquely provided with a plurality of fluidic micro-channels identified in the drawings as 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194 and 196. Each of the fluidic micro-channels is also provided with an outlet 162 a, 164 a, 166 a, 168 a, 170 a, 172 a, 174 a, 176 a, 178 a, 180 a, 182 a, 184 a, 186 a, 188 a, 190 a, 192 a, 194 a and 196 a, respectively.

As best seen in FIG. 36, upper side of rate control plate 160 is also uniquely provided with a plurality of fluidic micro-channels of different lengths that are identified in the drawings as 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234 and 236. Each of the fluidic micro-channels is also provided with an outlet 202 a, 204 a, 206 a, 208 a, 210 a, 212 a, 214 a, 216 a, 218 a, 220 a, 222 a, 224 a, 226 a, 228 a, 230 a, 232 a, 234 a and 236 a, respectively. Upper control plate 160 is also provided with inlet ports 250, 252, 254, 256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282 and 284 that communicate with the outlet ports 162 a through 196 a of lower side of control plate 160.

As best seen in FIG. 22, the inlet ports of the upper control plate as well as the outlet ports thereof communicate with a multiplicity of spaced apart fluid ports 290 formed in rate control distribution plate 292. From fluid ports 290, the fluid flows toward the novel fluid pickup housing 294 of the invention. As illustrated in FIGS. 23 and 24, fluid pickup housing 294 includes a base 294 a and tower portion 294 b that is provided with a multiplicity of circumferentially spaced apart generally vertically extending fluid passageways 296 of varying lengths.

With the construction described in the preceding paragraphs, fluid flowing from the fluid reservoir will fill fluidic micro channels 162 through 196 as well as fluidic micro channels 202 through 236 via an inlet port 297 carried by rate control distribution plate 292 (see FIGS. 19A, 21 and 22). Fluid flowing through the outlet ports of these fluidic micro-channels will flow into spaced apart fluid ports 290 formed in rate control distribution plate 292. From fluid ports 290, the fluid will flow into and fill the circumferentially spaced apart, generally vertically extending fluid passageways 296 of fluid pickup housing 294 (FIGS. 23, 24, 25 and 26). Referring to FIG. 27, which is a depiction of the outer surface of fluid pickup housing 294 when viewed in a planar configuration, it is to be noted that fluid passageways 296 are arranged in six spaced part groups of passageways 298, 300, 302, 304, 306 and 308 respectively. Each group of passageways is made up of six spaced apart passageways of a different length, each passageway having an outlet located at a different height with respect to base 294 a of the fluid pick-up housing (FIG. 24). From a selected one of the six groups of fluid passageways 296, the fluid will flow into a group of six vertically and circumferentially spaced apart inlets 310 (FIGS. 49 and 49A) formed in the skirt portion 312 a of a patient weight selector knob 312 (see also FIG. 22, which is a depiction of the outer surface of the skirt portion when viewed in a planar configuration). For a purpose presently to be described, the skirt portion 312 a of patient weight selector knob 312 is also provided with six circumferentially spaced apart outlet groups 314, each group having six vertically spaced apart outlet ports 316. From inlets 310, the fluid will flow into a plurality of vertically spaced apart, circumferentially extending fluid passageways 320 formed in a fluid pickup housing 322 (FIGS. 7, 28, 29 and 30) that is housed interiorly of the downwardly depending skirt 312 a of the patient weight selector knob 312 (see FIGS. 7, 20, 21 and 22), retaining tabs 325 that are disposed to interiorly of skirt 312 a (FIG. 47) properly and retain fluid pickup housing 322 within skirt 312 a.

With the construction described in the preceding paragraphs, fluid flowing from the fluid reservoir will fill fluidic micro channels 162 through 196 (FIG. 40) as well as fluidic micro channels 202 through 236 (FIG. 36), will fill the fluid passageways 296 of fluid pickup housing 294 (FIG. 24) and will fill the circumferentially extending fluid passageways 320 formed in a fluid pickup housing 322 (FIG. 22). From fluid passageways 320 the fluid will flow into the vertically spaced apart outlet passageways 316 formed in patient weight selector knob 312 (FIG. 7).

When the patient weight selector knob 312 is rotated into the position shown in FIG. 7, fluid will flow from outlet ports 316 into the six vertically spaced apart, transversely extending fluid passageways 330 formed in fluid pickup housing 294. As will presently be described, fluid passageways 330 communicate with the dose control means of the invention which, as previously mentioned, functions to control the dose of medicament to be delivered to the patient.

With the patient weight selector knob 312 in position (FIG. 47) wherein inlets 310 (FIG. 49A) align with one of the groups 298 through 308 (FIG. 27) of fluid passageways 296, fluid will flow from the fluid reservoir through inlet 297 (FIG. 22) into the fluidic micro-channels of different lengths formed in upper and lower surfaces of lower rate control plate 160 (FIGS. 36 and 40), into vertically extending fluid passageways 296 of fluid pickup housing 294 (FIG. 24), into inlets 310 (FIG. 22), into passageways 320 formed in the fluid pickup assembly 322, into passageways 316 of the patient weight selector knob 312, into passageways 330 of the fluid pickup assembly 294 and finally into passageways 332 of body portion 334 a of the dose control assembly 334 (see also FIG. 53A). It is apparent that the rate of fluid flow toward the dose control means depends upon the configuration of the rate control passageways formed in the rate control plate 160 that are in communication with inlets 310 via vertically extending fluid passageways 296. By way of example, assume that the patient weight selector knob 312 is rotated into a position wherein inlets 310 a, 310 b, 310 c, 310 d, 310 e and 310 f (FIG. 47A) align with the passageways 296 a, 296 b, 296 c, 296 d, 296 e and 296 f of group 298 (FIG. 27). Assume further, that the six passageways 296 a, 296 b, 296 c, 296 d, 296 e and 296 f are in communication with fluid passageways 162, 164, 166, 168, 170 and 172 respectively of rate control plane 160 (FIG. 40). In this situation, fluid will flow from fluid passageway 162 into passageway 296 a, then into passageway 310 a and finally into the lower most circumferentially extending passageway 320 a formed in the fluid pickup assembly 322 (FIG. 7). Similarly, in this situation, fluid will flow from fluid passageway 164 into passageway 296 b, then into passageway 310 b and finally into circumferentially extending passageway 320 b formed in the fluid pickup assembly 322 (FIG. 7). The fluid will flow in a similar manner from passageways 166, 168, 170 and 172 into the remaining circumferentially extending passageway 320 formed in the fluid pickup assembly 322

As illustrated in FIGS. 12 and 13 of the drawings, rate control indexing means are provided to position the locking knob 312 in a selected rotational position. In the present form of the invention, this rate control indexing means comprises a locking plunger 333 that is received within a bore 104 a formed in the forward portion 104 of housing 102. Locking plunger 333 is continuously biased outwardly, by a coiled spring 335 into locking engagement, with a selected one of a plurality of circumferentially spaced apart cutouts 312 c formed in the flange portion 312 b of the locking knob assembly 312. With this construction, in order to rotate the locking knob from the selected rotational position, the locking plunger 333 must be manually pushed inwardly against the urging of spring 335.

Turning now particularly to FIGS. 7 and 50 through 53, rotatably mounted within body portion 334 a of the dose control assembly 334 is the patient dose selector knob 338, formed within a body portion 338 a of the dose selector knob vertically spaced-apart radially outwardly extending fluid passageways 340, 342, 344, 346, 348 and 350. By rotating the dose selector knob within body portion 334 a, the radially outwardly extending fluid passageways can be selectively brought in to communication with the passageways 332 that are, in turn, in communication with the circumferentially extending passageway 320 formed in the fluid pickup assembly 322 of the rate control means of the invention. By way of example, in FIG. 7 of the drawings radially outwardly extending fluid passageway 340 is shown in communication with the uppermost passageway 332 of the dose control means. As illustrated in FIG. 51, each of the radially outwardly extending fluid passageways is in communication with an axially extending passageway 352 that is, in turn, in communication with the bolus operating mechanism of the invention, the character of which will presently be described.

By way of example, further rotation of the dose selector knob within body portion 334 a can bring radially outwardly extending fluid passageway 350 into communication with circumferentially extending passageway 320 a of fluid pickup assembly 322 via the lower-most passageway 332. In this situation, it can be seen that fluid passageway 350 is in communication with fluid passageway 162 of lower surface of rate control plate 160 via the lower most passageway 332, the lower most passageway 330, the lower most passageway 316, circumferentially extending passageway 320 a and passageway 296 a. Similarly, in this example, by controlled rotation of the dose selector knob, each of the fluid passageways formed in the dose selector knob can be brought into communication with a selected one of the passageways 164 through 172 formed in the rate control plate 160. In this way the rate of fluid flow toward the patient of the medicinal fluid contained within the device reservoir can be closely controlled.

As illustrated in FIGS. 12 and 14 of the drawings, dose control indexing means are provided to lock the patient dose selector knob 338 in any selected position. In the present form of the invention this dose control indexing means comprises a locking plunger 353 that is received within a bore 104 b formed in the forward portion 104 of housing 102. Locking plunger 353 is continuously biased outwardly by a coiled spring 355 into locking engagement with a selected one of a plurality of circumferentially spaced apart cutouts 338 c formed in the flange portion 338 b of the patient dose selector knob assembly 338. With this construction, in order to rotate the patient dose selector knob 338 from a selected position the locking plunger 353 must be manually pushed inwardly against the urging of spring 355.

As will be discussed in greater detail hereinafter, the bolus delivery means of the invention, which permits selected bolus doses of medicaments to be delivered to the patient from reservoir 360, includes a double bolus reservoir 360 and a bolus operating mechanism 384 that includes first and second operating shafts 386 and 387.

Considering further the bolus delivery means of the invention, this novel means, which is housed within forward portion 104 of housing 102, includes a double bolus reservoir 360 that is disposed within a cavity 359 formed in forward portion 104 of housing 102. The double bolus reservoir 360 is defined by interconnected, collapsible bellows structures 360 a and 360 b that are in communication with passageway 352 of the dose control means via a longitudinally extending passageway 362, a vertical stab passageway 364, a conventional umbrella check valve 366, a vertical stub passageway 368 and a longitudinal passageway 370 (see FIGS. 5 and 53A). Umbrella check valve 366, which is carried with an internal housing 372, functions to permit fluid flow toward reservoir 360, but blocks fluid flow in the opposite direction. Reservoir 360 is in fluid communication with the administration set 153 (FIG. 2) via passageway 374, a second conventional umbrella check valve 376, a vertical passageway 378 and longitudinally extending passageway 380. With this construction, low flow from the dose control means any selected dose, to bolus reservoir 360 and then on to the patient via the administration set 153.

Referring particularly to FIGS. 5A, 53A and 57-61, the important bolus operating mechanism of the invention is there shown and generally designated by the numeral 384. This mechanism permits selected bolus doses of medicaments to be delivered to the patient from reservoir 360 as may be required. As best seen in FIGS. 55 and 57 of the drawings, this novel mechanism here comprises a first, or main operating shaft 386 for controllably collapsing the bellows structure 360 a and a second operating shaft 387 (FIGS. 61, 62, 73, and 74) for controllably collapsing the bellows structure 360 b (see FIG. 59). By way of non limiting example, bellows structure 360 a can have a first volume of between approximately 3 ml and approximately 6.0 ml while bellows structure 360 b can have a second, lesser volume of approximately 0.5 ml and approximately 2.0 ml. Main operating shaft 386 controllably collapses bellows structure 360 a by pushing inwardly on the shaft against the urging of a coiled operating spring 388 that circumscribes bellows structure 360 a. In the manner illustrated in FIG. 55, main operating shaft 386 is movable within the reduced diameter portion 390 a of the bolus selector housing 390 that is carried within the forward portion 104 of housing 102. Following rotation of the bolus selector in a manner presently to be described, the main operating shaft can be moved inwardly against the urging of coiled operating spring 388 from an extended to an inward position. Inward movement of the main operating shaft causes inward movement of a pusher member 394 which, in turn, causes the collapse of the bellows portion 360 a. It is to be noted that pusher member 394 is provided with a yieldably deformable locking tab 394 a (see also FIG. 62) that is adapted to engage a plurality of generally saw-toothed shaped protuberances 396 that are formed on the inner wall of cavity 359. Locking tab 394 a is so constructed and arranged as to ride over protuberances 396 as the main operating shaft is pushed inwardly of cavity 359. However, the saw-toothed protuberances 396 are configured so that the locking tab will engage the vertical faces 396 a of the protuberances in a manner to prevent movement of the pusher member in a direction toward its starting position (FIG. 55). With this construction, once the reservoir bellows portion 360 a is collapsed, it will remain in a collapsed configuration.

Following rotation of the operating knob 399 of the bolus operating mechanism 384 in a manner presently to be described, second operating shaft 387 can be moved inwardly within a bore 386 a provided in main operating shaft 386 against the urging of a second coil spring 400. Second operating shaft 387 operates against bellows portion 360 b in a manner to collapse the bellows portion as the second operating shaft is urged inwardly against the urging of spring 400. As the bellows portion 360 b collapses, medicinal fluid contained there within will be urged outwardly of the reservoir via outlet passageway 378. However, upon the release of inward pressure exerted against second operating shaft 387, spring 400 will urge the operating shaft into its original starting position so that subsequent smaller bolus doses of medicament can be delivered to the patient.

Turning now to FIGS. 59, 60 and 61, in delivering bolus doses of medicament to the patient, a locking member 404 that is carried by housing 102 in the manner shown in FIG. 56 of the drawings must be pushed inwardly in order to permit rotation of the reduced diameter portion 390 a of the bolus selector housing 390. As indicated in FIG. 56, inward movement of the locking member causes the locking shoulder 404 a to move out of locking engagement with a cavity 390 c formed in the enlarged diameter portion 390 b of the bolus selector housing 390 so as to permit rotation of the bolus selector housing 390. With the locking member pushed inwardly, the bolus selector housing 390 can be rotated from the “off” position shown in FIG. 59 of drawings to the “5.0 ml” position. This done, the main operating shaft can be pushed inwardly causing plunger 394 to collapse bellows 360 a, resulting in the delivery of a bolus dose of a predetermined volume of medicament to the patient (in this case 5.0 ml). As previously mentioned, once the main operating shaft is pushed inwardly, it will be locked in position by locking tab 394 a.

When it is desired to deliver a smaller bolus dose of medicament to the patient, as, for example 2.5 ml, it is necessary to first rotate cap 399 from the “off” position shown in FIG. 77 to the “2.5 ml” position shown in FIG. 78. As best seen in FIG. 73 second operating shaft 387 is provided with a rotational stop 387 a that engages a stop wall 410 provided on the main operating shaft 390 (see FIGS. 64 through 67). As the second operating shaft is rotated, a coiled spring 412 carried a spring shelf 414 (FIGS. 66, 67 and 69) will resist the rotation and will be compressed in the manner in FIG. 70.

This done, the secondary operating shaft 387 can be pushed inwardly in the manner illustrated in FIG. 61. This inward movement of the second operating shaft will collapse bellows portion 360 b causing the fluid contained there within (in this instance 2.5 ml) to be delivered to the patient via outlet passageway 374.

With the construction described in the preceding paragraph, when the rotational forces exerted on cap 399 cease, spring 412 will urge the cap to return to its starting position and at the same time, spring 400 will urge shaft 387 into its starting position, thereby permitting a repeated application of a smaller bolus dose of medicament to the patient as may be required.

Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims. 

1. A dispensing device for dispensing a medicament to a patient comprising: (a) a device housing; (b) a reservoir defining assembly carried by said housing, said reservoir defining assembly including a collapsible reservoir having an inlet port and an outlet port; (c) stored energy means carried by said housing and operably associated with said reservoir defining assembly for collapsing said collapsible reservoir to expel fluid medicament therefrom, said stored energy means comprising a spring; and (d) fluid flow control means carried by said device housing for controlling the flow of medicament from said reservoir toward the patient, said flow control means comprising dose control means for controlling the dose of medicament delivered to the patient, said dose control means comprising a dose control assembly, including a rotatable patient dose selector knob and rate control means for controlling the rate of medicament flow from said collapsible reservoir toward said dose control means, said rate control means comprising a flow rate control assembly, including a rotatable patient weight selector knob and first and second rate control plates, each being provided with a plurality of fluidic micro-channels interconnected with said outlet port of said collapsible reservoir.
 2. The dispensing device as defined in claim 1 in which said stored energy means comprises a coil spring operably associated with said reservoir defining assembly.
 3. The dispensing device as defined in claim 1 in which said collapsible reservoir comprises a bellows structure.
 4. The dispensing device as defined in claim 1 further including fill means carried by said device housing for filling said collapsible reservoir with medicament, said fill means comprising a pierceable septum.
 5. The dispensing device as defined in claim 1 in which said rate control means further includes a rate control distribution plate and a fluid pickup housing having a plurality of spaced apart, fluid passageways that, upon rotation of said patient weight selector knob, communicate with said dose control means and in which said dose control assembly of said dose control means for selecting the medicament dose delivered to the patient includes a rotatable patient dose selector knob having a plurality of spaced-apart, radially outwardly extending fluid passageways.
 6. The dispensing device as defined in claim 1, further including a bolus delivery assembly carried by said device housing for delivering bolus doses of medicament to the patient.
 7. A dispensing device for dispensing a medicament to a patient comprising: (a) a device housing; (b) a reservoir defining assembly carried by said housing, said reservoir defining assembly including a collapsible reservoir having an inlet port and an outlet port; (c) a spring carried by said housing and operably associated with said reservoir defining assembly for collapsing said collapsible reservoir to expel fluid medicament therefrom; and (d) a flow rate control assembly carried by said device housing for controlling the rate of flow of medicament from said reservoir to the patient, said flow rate control assembly including: (i) a first rate control plate having a plurality of fluidic micro-channels interconnected with said outlet port of said collapsible reservoir; (ii) a second rate control plate connected to said first rate control plate and having a plurality of fluidic micro-channels in communication with said plurality of fluidic micro-channels of said first rate control plate; (iii) a rate control distribution plate connected to said second rate control plate and having a plurality of fluidic channels in communication with said plurality of fluidic micro-channels of said second rate control plate; (iv) a fluid pickup housing connected to said rate control distribution plate, said fluid pickup housing having a plurality of spaced apart, fluid passageways in communication with said plurality of fluidic micro-channels of said rate control distribution plate; and (v) a rotatable patient weight selector knob operably associated with said fluid pickup housing, said rotatable patient weight selector knob having a plurality of circumferentially spaced fluid ports in communication with said plurality of spaced apart, fluid passageways of said fluid pickup housing; (e) a dose control assembly carried by said device housing and operably associated with said flow rate control assembly for controlling the dose of medicament flowing from said reservoir to the patient, said dose control assembly comprising a rotatable patient dose selector knob having a fluid passageway in communication with said plurality of spaced apart, fluid passageways of said fluid pickup housing; and (f) an administration set connected to said device housing and in communication with said dose control assembly.
 8. The dispensing device as defined in claim 7 in which said fluid pickup housing has a plurality of vertically extending, circumferentially spaced apart, fluid passageways in communication with said plurality of fluidic micro-channels of said rate control distribution plate.
 9. The dispensing device as defined in claim 7 in which said rotatable patient weight selector knob has a plurality of vertically spaced apart, fluid passageways in communication with said plurality of passageways of said fluid pickup housing.
 10. The dispensing device as defined in claim 7, in which said dose selector knob has a plurality of vertically spaced apart, radially extending fluid passageways in communication with said passageways of said pickup housing.
 11. The dispensing device as defined in claim 7, further including a bolus delivery assembly carried by said device housing and in communication with said dose control assembly for delivering bolus doses of medicament to the patient.
 12. The dispensing device as defined in claim 11 in which said bolus delivery assembly includes a double bolus reservoir comprising interconnected collapsible bellows structures.
 13. The dispensing device as defined in claim 12 in which said bolus delivery assembly includes a bolus operating mechanism comprising a first operating shaft for controllably collapsing a selected one of said collapsible bellows structures and a second operating shaft for controllably collapsing another of said collapsible bellows structures. 